Surfactant water modified Silica Nanoparticle molecular interaction / Megat Ariff Megat Abdullah

The involvement of Nano Technology and silica in the foam formation plays an important role to enhance the oil recovery. However, its molecular dynamic interface abilities and interactions behavior were not widely known. The challenge in the foam flooding was foam created was easy to break. It was difficult to maintain the stability of foam created when comes in contact in the reservoir due to the lower of viscosity effect. Thus, the molecular interactions behaviors and understanding the structural and dynamic information of the absorption of Alpha Olefin Sulfonate (AOS) on the interface of water and air was conducted using molecular dynamic simulations in Material Studio 7. The modification of silica nanoparticles (SNP) demonstrated by attachment of Hexyl-trimethoxysilane (HTMS) on SNP surface. From the simulation, the data such as Mean Square Displacement (MSD) and Cohesive Energy Density (CED) were extracted as measurement to investigate the diffusivity and water-air surface tension, respectively. The diffusivity of AOS in the system that using modified SNP was higher than SNP without HTMS which was 0.3099 Ȧ²/ps and 0.2891 Ȧ²/ps, respectively. In addition, the surface tension for the system with HTMS was lower than surface tension for SNP without HTMS which was 1.80x10¹⁰ GPa and 2.39x10¹⁰ GPa, respectively after 100 ps. These result indicated that the modified SNP with HTMS improved the adsorption of the surfactant. Thus, the foam stability was slightly higher with the presence of HTMS on SNP surface.